Welcome to HVAC-Talk.com, a non-DIY site and the ultimate Source for HVAC Information & Knowledge Sharing for the industry professional! Here you can join over 150,000 HVAC Professionals & enthusiasts from around the world discussing all things related to HVAC/R. You are currently viewing as a NON-REGISTERED guest which gives you limited access to view discussions

To gain full access to our forums you must register; for a free account. As a registered Guest you will be able to:

Participate in over 40 different forums and search/browse from nearly 3 million posts.

DX geothermal what do you think

licensed refrigeration guy here installed a bunch of pump and dump geo units with lots of success. I am building my own house and was thinking out options for heating /cooling i was looking at my first direct expansion geothermal unit. My lot is difficult to dig so the smaller loop footprint would be a bonus and all equipment / install is at my cost . What do you guys think for best system. My house is in northern ontario canada and will be 2000 sq feet. Thanks alot

I have never done a DX so take my opinion as nothing more than an opinion. I do not see how putting copper in the ground can be a good thing over time. I have heard from associates that these do not last much longer than 10 years due to the copper lines falling apart over time. At that point you have then leaked refrigerant into the ground and have to redrill everything. I prefer do it once and do it right. The copper has a 5 year warranty on the pipe and is much thicker than regular copper but HDPE pipe has 55 year warranty so which would you trust under the ground?

Also Because of the extreme heat transfer of straight refrigerant i have heard that the ground can start to freeze and expand and contract causing a rolling effect of the ground around it. Also after 3-5 years of freezing ground, now the earth is no longer touching your pipe and the efficiency drops fast.

In short, first 1-5 years can be amazing efficiency and no issues
5+ years expect efficiency to drop off each year and many possibilities of pipes breaking underground and re-excavating.

I have never done a DX so take my opinion as nothing more than an opinion. I do not see how putting copper in the ground can be a good thing over time. I have heard from associates that these do not last much longer than 10 years due to the copper lines falling apart over time. At that point you have then leaked refrigerant into the ground and have to redrill everything. I prefer do it once and do it right. The copper has a 5 year warranty on the pipe and is much thicker than regular copper but HDPE pipe has 55 year warranty so which would you trust under the ground?

Also Because of the extreme heat transfer of straight refrigerant i have heard that the ground can start to freeze and expand and contract causing a rolling effect of the ground around it. Also after 3-5 years of freezing ground, now the earth is no longer touching your pipe and the efficiency drops fast.

In short, first 1-5 years can be amazing efficiency and no issues
5+ years expect efficiency to drop off each year and many possibilities of pipes breaking underground and re-excavating.

Actually, none of that is true. If copper breaks down in the ground...why is there copper considering it comes from the ground. Dirt, for the most part, is reducing....it adds electrons to the copper, instead of removing it.....

sounds like what you've "heard" is a well driller or hvac contractor well vested in vertical boring. DX systems existed before water source systems, have an EXTREMELY low failure rate ( due mostly to the fact they dont over complicate them with electronics....) as far as freezing the ground...its grouted...thermal grout wont freeze bc it will disperse energy in as even a fashion as it can be expected to. The only time you'd experience any thing like that is if the system was grossly undersized ( they are designed for a 12/12 run/rest cycle) water source has its applications....but dx definately does as well.....problems occur when you get an ignorant contractor...as with anything